Solving quadratic equation of one variable: x-3x + 1 = 0 and 2x + 6 = 7x and 3x-9x + 2 = 0

Solving quadratic equation of one variable: x-3x + 1 = 0 and 2x + 6 = 7x and 3x-9x + 2 = 0

2X + 1 = 2x ^ 2-3x + 9 / 4-9 / 4 / 4 + 1 = 0 (x + 3 / 2) ^ 2-5 / 4 = 0 (x + 3 / 2 + 5 / 2) (x + 3 / 2 - √ 5 / 2) (x + 3 / 2 / 2 - √ 5 / 2 / 2) = 0x = - √ 5 / 2-3 / 2 or x = √ 5 / 2-3 / 22x square + 6 = 7x2x ^ 2-7x + 6 = 0 (2x-3) (X-2) = x = 3 / 2 or x = 23x-9x-9x + 2 + 2 = x ^ 2-3x + 2 / 2 / 3 = x ^ 2-3x + 2 / 3 = x ^ 2 ^ 2-3x + 2 / 3 = 2x ^ 2 ^ 2 ^ 2-2x + - 3x + 9 / 4-9 / 4 + 2 / 3 = 0x ^ 2-3x + 9 / 4-57 /

(2x ^ 3 + 4x + 7) + (8x ^ 3-6-4x ^ 2) - (- 5x ^ 3 + 7-6x-5x ^ 2) is calculated by direct formula

Friendly platoon
(2x³+4x+7)+(8x³-6-4x²)-(-5x³+7-6x-5x²)
=2x³+4x+7+8x³-6-4x²+5x³-7+6x+5x²
=15x³+x²+10x-6

Reduced fraction: 5x x2+x−6+2x−5 x2−x−12−7x−10 x2−6x+8

Original formula = 5x
(x+3)(x−2)+2x−5
(x+3)(x−4)-7x−10
(x−2)(x−4)
=5x(x−4)+(2x−5)(x−2)−(7x−10)(x+3)
(x+3)(x−2)(x−4)
=−40x+40
(x+3)(x−2)(x−4)．

2x-1-2 parts 5x + 1 is less than or equal to 1, 5x-1 is less than 3 (x + 1)

2x-1-2 parts 5x + 1 is less than or equal to 1 and multiplied by 6 on both sides
2（2x-1）-3(5x+1)≤6
4x-2-15x-3≤6
-11x-5≤6
-11x≤11
x≥-1
5x-1

Given that 5x-3x-5 = 0, then 5x ^ - 2x-1 / 5x ^ - 2x-5 = ()

It's 5x ^ 2-3x-5 = 0
Then 5x ^ 2-2x-5 = x
5x^2-2x=x+5
5x^2-5=3x
So x ^ 2-1 = 3x / 5
So the original formula = x + 5-1 / X
=(x^2+5x-1)/x
=(3x/5+5x)/x
=3/5+5
=28/5

How to calculate 3 (2x-1) - 4 (5x + 1) = 12 (x + 1)

3（2x-1)-4(5x+1)=12(x+1)
6x-3-20x-4=12x+12
12x+6x+20x=-3-4-12
38x=-19
x=-19÷38
x=-1/2

To solve the equations: 1. {3x + 2Y = 142. {x-5y = 0 3. {x {2 + y} 3 = 2 {x = y + 3 {3x + 2Y = 17 {0.2x + 0.3y = 2.8

3x+2y=14 ①
x-5y=0 ②
① - 2 × 3
17y=14
y=14/17
By substituting y = 14 / 17 into (2), we can get: y = 14 / 17
x-5·14/17=0
x=70/17
3x+2y=17 ①
0.2x+0.3y=2.8 ②
② The result of × 10 is as follows:
2x+3y=28 ③
① × 2 - 3 × 3 is obtained
6x+4y-6x-9y=34-84
y=10
When y = 10 is substituted into ①, the result is as follows:
3x+20=17
x=-1

If two systems of equations about X and Y 2x−y＝b X − y = A and 3x−2y＝b+1 3Y − 5x = a − 8 has the same solution

In equations (1), ① - ②, x = b-a,
2 (B-A) - y = B,
y=b-2a．
The solution of equation (1) is
x＝b−a
y＝b−2a ．
Substituting (2), we get
3(b−a)−2(b−2a)＝b+1
3(b−2a)−5(b−a)＝a−8 ，
The solution
a＝1
b＝3 ．

If the square of 2x plus 3x plus 7 is 8, what is the value of the square of 4x plus 6x minus 9? If a minus B equals 2, a plus C equals 6, (2a + B + C) - 2 (a)_ B_ c) Equal to

2X^2+3X＋7＝8
2X^2+3X＝1
4X^2+6X－9=2(2X^2+3X)-9＝-7
a-b＝2
a+c＝6
So (a + C) - (a-b) = 4 = B + C
So (2a + B + C) - 2 (a-b-c) = 2A + B + C-2A + 2B + 2C = 3B + 3C = 12

When x takes what number, the values of the algebraic expressions 4x-3 and 3 (1-2x) are opposite to each other?

Because they are opposite numbers
So 4x - 3 + 3 (1 - 2x) = 0
4x - 3 + 3 - 6x = 0
6x - 4x = -3 + 3
2x = 0
x = 0